Separable insulator-thimble structure.



Patented Mar. 20, 1917.

2 SHEETS-SHEET UNITED sTATEs PATENT oEEIoE.

CHARLES L. PEIROE, JR., OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO HUBBARD & 00., OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANIA.'

Application filed May 17, 1916.

To all whom it may concern:

Be 'it known that 1, CHARLES L. PEIR E, Jr., a citizen. of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in separable Insulator-Thimble Structures, of which the following is a specification.

My invention relates to separable thimble supports for the larger type of insulators intended for service in high voltage transmission systems;

Insulators for high voltage service are large and usually of porcelain, and owing tothe differences in shrinkage in different lots of clayit is practically impossible to produce such porcelain insulators with accurately threaded bores, and the insulators cannot therefore be screwed directly onto unyielding pins or thimbles without breaking or straining them. It has therefore been theusual practice to cement thimbles into the insulators, the thimbles being threaded on their inner sides to accurately and snugly fit supporting pins and having also threads on their outer sides, but the outer diameter being smaller than that of the threaded bore of the insulators in order to leaveroom for cement between the thimble and insulator, the cement getting a firm hold on the thimble outer threads and on the insulator bore threads to rigidly secure it in place. Such insulators with the thimbles therein are then screwed onto pins. It has, however, been found desirable in some instances to have the .thimbles separable in the insulators and the object of my invention is to produce efficient separable thimble structures.

Such separable thimble structures must have internal threads for accurately and snugly fitting the threads of pins and must have yielding and resilient outer threads for accommodating the threadingof the insulator bore which, as above stated, is not always accurate and true; The separable insulator structures of my invention meet with these requirements and on the accompanying drawings such structures are shown. On these drawings- Figure lis an elevational view of a pin with one form of improved separable thimble' structure thereon together with an insulator in vertical diametral section,

Specification of Letters Patent.

SEPARABLE INSULATOR-THIMBLE STRUCTURE.

Patented Mar. 20, 191 7.

Serial No. 98,032.

Fig. 2 is a similar view of the upper end of the pin showing a modified separable thimble structure,

' Fig. 3 is a top view of the thimble structure of Fig. 2,

Fig. T is a view of the upper end of a pin with a modified form of thimble structure and an insulator mounted thereon, the thimble structure and insulator being in vertical diametrai section, and

Fig. 5 is an elevational view of the hood shown in Fig. 4:.

Referring to Fig. 1, p represents a pin which is cylindrical at its upper end and provided with threads 10. The thimble structure shown comprises an inner thimble member 11 in the form of a cap whose cylindrical sides are pressed orrolled to form inner threading 12 and outer threading 13, this inner thimble structure being adapted to intimately fit over the end of the pin with its inner threading 12 intimately engaging with the pin threading 10. The thimble structure has the outer thimble member 14 shown in the form of a wire helix whose turns parallel the turns of the external threading 13 of the inner thimble member 11. The ends of the wire helix deflect into upper and lower slots 15 and 16 respectively cut into the inner thimble member, the slots permitting circumferential play of the helix ends. The outer surface of the helix turns is adapted to receive the thread ed bores of insulators, such as I, and when an insulator is applied the coeperation of the helix with the inner thimble member is substantially the same as the cooperation of the helix with its support in my Patent No. 1,158,1 .-9, dated October 26, 1915. The helix is yieldable radially helically and its turns are relatively bodily yieldable so that this outer thimble structure is very resilient and very readily accommodates itself to the ordinary irregularities in the threading of large sized insulators. The thimble structures can also be very readily inserted in or withdrawn from the insulator. lVhen the thimble structure is started into the insulator the upper end of the helix will be anchored against the outer edge of the slot 15 so that the remainder of the helix will be free to contract helically to the extent of the lower slot 16 and the structure can therefore be very readily inserted into the insulator. hen rotated in reverse direction to eliect Withdrawal the lower end of the helix anchors against the outer edge of the slot 16 and the upper part of the helix'can contract so that Withdrawal can very easily be accomplished. However, when the structure is fully Within the insulator the spring of the helix will cause the turns to expand and clamp themselves securely against the threading of the insulator so that the structure is securely locked in the insulator. The thimble structure can, of course, be first inserted into the insulator an the inner thimble member 11 then applied to the pin, or the thimble structure can be first applied to the pin and the insulator then applied thereto.

In Figs. 2 and 3 a modified form of separable thimble structure is shown. The structure is in the form of a sheet metal cap 17 from whose sides longitudinal sections 18 are stamped and deflected outwardly. Before deflecting the sections the cap is rolled or pressed to provide internal threading 19 for intimately engaging the threading 10 of the pin 9, and then when the sections 18 are deflected they Will have outer threading 20 for engaging with the threading of the insulator such as I. These tongues 18 deflected from the thimble structure cap thus provide the resilient and yielding threaded seating for the threading of the insulator which may be more or less inaccurate and irregular. To strengthen the tongues their lower ends 21 may be deflected inwardly and rounded at their lower ends to abut against and fit the pin threading 10. This sheet metal thimble structure can be readily inserted in or withdrawn from the insulator and when in place on the pin will afford a secure yet resilient and yielding support for the insulator.

In Fig. 4 is shown another arrangement. Here the inner thimble structure is in the form of a sheet metal cap 22 rolled to provide internal threading 23 for engaging the pin threading 10 and to provide external threading 24. A cap or hood 25 of pliable material, such as felt, is slipped over the sheet metal thimble 22 and is of a thickness to snugly fill, under more or less compression, the space between the thimble 22 and the sides of the bore of the insulator I and by virtue of such compression to fit snugly against the threading 2 1 of the thimble and against the threading ot' the insulator bore. It is evident, 01 course, that the sheet metal inner thimble member 22' can be omitted and the fabric cap applied directly over the threaded end of the pin. The hood gives the resilient and yielding seating for the insulator and the thimble structure can be readily inserted in or withdrawn from the insulator.

I thus provide thimble structures which have inner threading for intimately and snugly receiving the threaded end of a pin, and which have yielding outer threading to form resilient seating for insulators. I do not of course desire to be limited to the exact constructions and arrangements shown as modifications are no doubt possible which would still come within the scope of the invention.

I claim as follows:

1. A detachable thimble structure comprising outer and inner members, the outer members being resilient and providing threading for receiving and clamping an insulator, the inner member forming a support for the outer members and being threaded to fit an insulator pin.

2. A detachable thimble structure comprising an inner sheet metal cap member threaded to lit asupporting pin, and outer thread members yieldably supported on the inner member and providing flexible threading for receiving and clamping an insulator.

3. A thimble structure comprising a sheet metal inner member threaded to fit a supporting pin, and an outer member in the form of a wire helix supported on the inner member and providing flexible threading turns for receiving and clamping an insulator.

In witness whereof I hereunto subscribe my name this 11th day of May, A. D., 1910.

CHARLES L. PEIRGE, JR.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents,

Washington, D. G. 

